Process of Environmental Impact Assessment - Stages in EIA
The first step of EIA process to decide whether or not EIA is required. It is a preliminarily study to investigate the negative and positive impacts of a proposed project. The project type and size is used to evaluate the extent of potential environmental impacts. Small projects some time have more adverse environmental effects than larger projects . Therefore, the
Scope, Benefits and Problems in Environmental Impact Assessment
The study of EIA effectiveness shows a number of difficulties and constraints, generally although not universally applicable, that continue to prevent and hinder EIA from consistently delivering these advantages and benefits:
What is Environmental Impact Assessment and its Objectives
An environment impact Assessment is an event or effect, which results from a prior event. It can be described as the change in an environmental parameter, over a specific period and within a defined area, resulting from a particular activity compared with the situation which would have occurred had the activity not been initiated.
Types of Activated Sludge Process - Plug Flow, Complete Mix, SBR
In CMAS, mixing of tank contents is sufficient so that ideally concentrations of mixed-liquor constituents, soluble substances (COD, BOD, NH4-N), and colloidal and suspended solids do not vary with location in aeration basin. Plug Flow involves relatively long and narrow aeration basins so that concentration of soluble substances and colloidal and suspended solids
Microbial Metabolism in Biological Waste Water Treatment
Carbon and Energy Sources for Microbial Growth: Organism must have sources of energy, carbon for synthesis of new cellular material, and inorganic elements (nutrients) such as nitrogen, phosphorus, sulfur, potassium, calcium and magnesium; Carbon Sources: Organisms that use organic carbon for formation of new biomass are called heterotrophs; Organisms that derive cell carbon from carbon dioxide are called autotrophs
Biological De-Nitrification Process in Waste Water Treatment System
Biological reduction of nitrate to nitric oxide, nitrousoxide, and nitrogen gas. Involves both nitrification and denitrification. Biological nitrogen removal (BNR) is more cost effective and used more often as compared to ammonia stripping, breakpoint chlorination and ion exchange; BNR is used in wastewater treatment where: there are concerns for eutrophication;
Biological Nitrification Process in Waste Water Treatment System
Total concentration of organic and ammonia nitrogen in municipal wastewater in the range 25‐ 45 mg/L as nitrogen based on flowrate of 450 L/capita.d (120 gal/capita.d). With limited water supplies, total nitrogen in excess of 200 mg/L as N measured in domestic wastewater. Drinking water maximum MCL for nitrate nitrogen is 45 mg/L as nitrate or 10
Sources of Drinking Water
Streams, rivers and lakes are the major sources of surface waters. Usually these sources fulfill the requirements of municipal supplies. Water in these sources originates partly from groundwater outflows and partly from rainwater which flows over the terrestrial areas into the surface water bodies. Outflows from groundwater brings in, the dissolved solids.
What is Disinfection and Methods of Disinfection of Water
In the water treatment processes, pathogens & other organisms can be partly physically eliminated through coagulation, flocculation, sedimentation, & filtration, in addition to the natural die-off. After filtration, to ensure pathogen free water, the chemical addition of chlorine (so called chlorination), rightly or wrongly, is most widely used for disinfection of drinking water
Chemical Characteristics of Sewage - BOD, COD, Nutrients, DO
In sanitary sewage about 75 % of suspended solids and 40% of filterable solids are organic. These solids are derived from both animals, plant and humans. Organic compounds usually consist of C; H; O; N along with S; P and Iron. The organic substances found in sewage are Protein (40-60%); Carbohydrates (25-50%), fats and oils (10%). Along with these organic
